12123220121221 has 12 divisors (see below), whose sum is σ = 13512708112320. Its totient is φ = 10786617494360.

The previous prime is 12123220121209. The next prime is 12123220121267. The reversal of 12123220121221 is 12212102232121.

It is not a de Polignac number, because 12123220121221 - 2⁷ = 12123220121093 is a prime.

It is a super-2 number, since 2×12123220121221² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12123220121192 and 12123220121201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12123220121021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 249434941 + ... + 249483538.

It is an arithmetic number, because the mean of its divisors is an integer number (1126059009360).

Almost surely, 2^{12123220121221} is an apocalyptic number.

12123220121221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12123220121221 is a deficient number, since it is larger than the sum of its proper divisors (1389487991099).

12123220121221 is an equidigital number, since it uses as much as digits as its factorization.

12123220121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 498918584 (or 498918537 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 22.

Adding to 12123220121221 its reverse (12212102232121), we get a palindrome (24335322353342).

The spelling of 12123220121221 in words is "twelve trillion, one hundred twenty-three billion, two hundred twenty million, one hundred twenty-one thousand, two hundred twenty-one".